Indonesia's most recent elections have been dubbed the most polarising in over 50 years. In 2017, the Christian Chinese governor of Jakarta, Basuki Tjahaja Purnama (better known as Ahok), was ousted following a series of Islamist-led protests that resulted in his conviction on blasphemy charges. The 2019 presidential election between Joko Widodo (Jokowi) and Prabowo Subianto was no less divisive: many in the Prabowo camp claimed that Jokowi was anti-Islamic or even a communist, and many on Jokowi's side asserted that Prabowo's ‘radical’ Islamist supporters were seeking to turn Indonesia into an Islamic theocracy. Muslim voters were divided along ethnic and ideological lines: Javanese traditionalist Muslims overwhelmingly voted for Jokowi, while more puritan, modernist Muslims in the outer islands largely backed Prabowo (Shofia and Pepinski 2019). An unprecedented 97 per cent of non-Muslims voted for the ‘pluralist’ Jokowi, even though his running mate, Ma’ruf Amin, was widely known for his deeply conservative politics (Indikator Politik Indonesia 2019).

This kind of identity-based polarisation has serious consequences for democratic quality. Comparative studies emphasise that political polarisation makes normal democratic competition seem an existential battle between two sides with mutually exclusive identities. This in turn prompts voters to view elections as a zero-sum game, and both sides become willing to accept less democratic strategies and rules if it means ensuring their candidate wins office (García-Guadilla and Mallen 2018; McCoy et al. 2018). As other contributions to this volume explain, political polarisation in the Jokowi era has already begun to erode liberal democratic norms and institutions in this way (see Hicken, this volume). The Jokowi administration's constraints on opposition actors and Prabowo's initial refusal to accept the 2019 election results are two powerful examples of the anti-democratic implications of a more polarised electoral atmosphere (see Warburton, this volume).

In this chapter, I examine the role of Islamic organisations and leaders in producing a more polarised political climate and, in turn, a less democratic Indonesia. Much recent literature focuses on one part of the equation: the increasing political significance of hardline Islamist organisations (e.g. Arifianto 2019; IPAC 2018; Mietzner and Muhtadi 2018). I look instead at the ‘militant pluralist’ counter-mobilisation spearheaded by Indonesia's largest traditionalist organisation, Nahdlatul Ulama (NU).